Plural stage residue hydrodesulfurization process with hydrogen sulfide addition and removal

Claim 1

A PROCESS FOR HYDRODESULFURIZING A FEED RESIDUAL PETROLEUM OIL CONTAINING ASPHALTENES, METALS AND SULFUR WITHOUT A DISTILLATION OR A SOLBENT EXTRACTION STEP FOR REMOVAL OF ASPHALTENES COMPRISING PASSING SAID FEED OIL THROUGH A PLURALITY OF HYDRODESULFURIZATION STAGES IN SERIES INCLUDING AN INITIAL STAGE AND A FINAL STAGE EACH OPERATING AT A TEMPERATURE BETWEEN ABOUT 650* AND 800*F., EACH STAGE EMPLOYING A CATALYST COMPRISING GROUP VI AND GROUP VIII METALS ON ALUMINA, INCREASING THE TEMPERATURE IN EACH STAGE WITH INCREASING CATALYST AGE TO COMPENSATE FOR CATALYST ACTIVITY AGING LOSS, MAINTAINING A LOWER HYDROGEN PRESSURE IN SAID FINAL STAGE THAN IN SAID INITIAL STAGE, REMOVING ASPHALTENES, METALS AND SULFUR FROM THE FEED OIL IN SAID INITIAL AND FINAL STAGES WITH A GREATER AMOUNT OF METALS AND SULFUR BEING REMOVED FROM THE FEED OIL IN SAID INITIAL STAGE THAN IN SAID FINAL STAGE, OPERATING SAID FINAL STAGE AT A HYDROGEN PRESSURE BETWEEN 1,300 AND 1,900 PSI AND OPERATING SAID INITIAL STAGE AT A HYDROGEN PRESSURE UP TO 2,300 PSI WHICH IS HIGHER THAN THE PRESSURE IN SAID FINAL STAGE SO THAT THE RATIO OF PERCENT DEMETALLIZATION TO PRECENT DESUFLURIZATION IS HIGHER IN THE FINAL STAGE THAN IN THE INITIAL STAGE INCLUDING GASEOUS HYDROGEN SULFIDE OR AN ADDED HYDROGEN SULFIDE PRECURSOR IN THE STREAM ENTERING THE FINAL STAGE, THE CATALYST IN SAID FINAL STAGE COMPRISING A HIGHER WEIGHT PERCENT OF GROUP VI AND GROUP VIII METALS THAN THE CATALYST IN SAID INITIAL STAGE SO THAT THERE IS A GREATER PERCENTAGE REUCTION IN ASPHALTENES IN SAID FINAL STAGE THAN IN SAID INITIAL STAGE, AND RECOVERING A HYDRODESULFURIZED EFFLUENTT FROM SAID FINAL STAGE COMPRISING MORE THAN 80 VOLUME PERCENT YIELD BOILING ABOVE THE GASOLINE RANGE BASED ON SAID FEED RESIDUAL OIL.